I saw a lot of that at a recent sci-fi thing, walking around London - I was the only one of typical student age in a group of four, and some drunk guy walking by us (to our ever-lasting amusement) started going "Students, you rock! Do what you do!" :oD But really, most of the 30/40-somethings hardly looked a day over 25. Something about sci-fi must keep people young :o)